Equalizing device



//v VENTO/i, 6A MUEL d. MORA/v S. J. MORAN EQUALIZING DEVICE F'iled Aug.27, 1940 Feb. 10, 1942.

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Patented Feb. 10, 1942 EQUALIZING DEVICE Samuel J. Moran, Los Angeles,Calif., assigner to Sumner C. Bryant, trustee, Los Angeles, Calif.

Application August 27, 1940, Serial No. 354,348

(Cl. IS7- 1) 7 Claims.

This invention relates to devices for equalizing the strain in aplurality of tension members. It is of particular utility for use inconnectionwith elevators and elevator cables and, for the purpose ofillustration, will be described in connection therewith, although I donot intend tc be limited to such use as the device is susceptible of usein many different fields of industry. Y,

This invention is an improvement on the construction shown in my PatentNo, 1,912,537y issued June 6, ,1933, to which reference ishereby made.

It is well known that when a unitary tensile force is applied to anobject through a plurality of members, suchfas cables, one of thesemembers may have a tendency to stretch andrthat such stretching actionthrows nearly all Aof the load upon the other members. It is the primaryobject of this invention to produce a device which may be employed inattaching members of the class referred to above to the object, suchdevice being constructed soas to effect an automatic adjustment in thelength of the members which will bring about an equalization of forcesamong the various members.

It is well known to those familiar with the elevator art that the usualconstruction Yemployed in elevators consistsof acage which is suspendedin the elevator shaft by a plurality of cables, such cables running overa power drum in the top of the shaft and extending downwardly throughthe shaft to form loops having their lower end portions-attached to thebottom of the cage. Counterweights are of course attached to the cablesat their intermediate portions. In structures of this nature it Ahasbeenfound that after a comparatively brief period of use one or more of thecables has a tendency-to stretch. This throws practically the entireload of the cage upon the other cables, and to compensate for thisstretching action the cables are usually attached to the top of the cagethrough the medium of turn-buckles or other similar adjustableconnection.

It has been found practically impossible to maintain uniform tension inthe cables through the use of manual adjustments ofthe type referred toabove. Numerous attempts have been made to perfect an attaching memberfor use in connecting cables of this nature to the elevator cage whichwill automatically maintain an equal strain in all of the tensionmembers.

It is a further object of this invention to produce an equalizing deviceof the class described which contains a non-fluid equalizingmedium.

CII

The lgeneral construction of the device contemplated by this inventionconsists of .a housing provided with a chamber -containing a pluralityof plungerfmembers. Each of the plunger members is attached to one ofthe tension members, and the chamber is iilled with a yieldable nonuidmedium, which in the preferred form of my invention consists of a bodyof metal spheres or ball bearings. It is in the manner in which suchball bearings are positioned relative to the plunger members in which mypresent invention is an improvement over that disclosed in my saidPatent No. 1,912,537,

Other objects and advantages will be apparent from the followingspecification and the drawing,which is for the purpose of illustrationonly, and in which:

Fig. 1 isa side view, partly in section, showing one side of myinvention connected to a plurality of cables;

Fig. 2 isa cross-sectional view taken on the line X-X of Fig. 1.

Referring to the drawing, Fig 1 shows a retaining means IIJ, adapted tobe suitably secured to an elevator cage (not shown) or other device tobe lifted, as described in my said Pat.- ent No, 1,912,537. Slidably`received in the retaining means I0 are plunger means I I comprising aiirst set of plungers I2, I3, and Illy and a second set of plungers I2a,I3a,.and Illa, as best shown in Fig. 2. Since the two sets of plungersoperate in the same manner, only the first set comprising the plungersI2, I3, and I4 will be described herein. Adapted to separate the plungermeans II from the retaining means IQ, and to maintain a rigid connectiontherebetween, is a 'bearing means I5 comprised ofa continuous chain ofseparate ball bearings I6.

Since the plungers I2, I3, an-d I4 are all similarly secured relative tothe retaining means ID., the manner is which the plunger I2 is securedwill be described in detail, omitting the specific detailed constructionof the retaining means for the other plungers.

The retaining means I0 is comprised of a central vertically disposedmember I'I to which is secured a rst end member I8 by means of bolts I9and 2l), the bolts 2U also securing relative to the first end member I8and the central member I1 a i'lrst track means 2| comprising a'lowerportion 22 and an upper separate portion 23. The lower portion 22 of therst track means 2I is provided with a centrally disposed longitudinalgroove 24 which terminates just below the upper end of the lower portion22 in a shoulder V25. Also formed in the lower portion 22 'of the rsttrack means 2| is a cup-shaped longitudinal bearing groove 21 axiallyaligned with the longitudinal groove 24 and in which the ball bearingsI6 are adapted to be received. As will be noted, the upper end of thelower portion 22 of the rst track means 2| is rounded, as at 28, and thebearing groove 21 -continues around the periphery thereof. The upperportion 23 of the first track means 2| is provided with a semi-circularopening 29 mating with the rounded end 28 of the lower portion 22, andhaving thereinY a bearing groove 30 mating with the bearing groove 21,to form a top bearing passage 3| adapted to receive the ball bearingsI6.

The plunger I2 is comprised of an upper member 34 and a lower member 35adapted to be held rigid relative to each other by longitudinal straps36 and 31 secured together at their lower ends by rivets 38 passingthrough the straps and the lower member 35, and secured together attheir upper ends by a rivet 39. The lower end of the upper member 34 isrounded to form a semi-circular end 49 which mates with the concavelyrounded upper end of the lower member 35. A cup-shaped groove 4| isprovided entirely around the edge of the upper member 34 and cooperateswith the bearing groove 21 of the first track means 2| to retain theball bearings II therebetween. The lower member 35 is provided with aconcave upper end mating with the lower rounded end 40 of the uppermember 34, and has formed therein a cup-shaped groove 43 complementaryto the groove 4| in the upper member to confine the ball bearings I6therebetween, the lower member 35 being provided with inner and outerplates 44 and 45 respectively, held in place by the longitudinal straps36 and 31. Also formed on the lower member 35 is a tongue 45 slidablyengaging in the longitudinal groove 24 of the rst track means 2| andlimited in its upward motion therein by the shoulder 25. Also formed inthe upper member 34 of the plunger I2 is a longitudinal groove 41 havinga shoulder 48 at its lower end, the groove being adapted to receive atongue 48 formed on the upper portion 23 of the first track means 2|,engagement of the shoulder 48 with the lower end of the tongue 49operating as a stop to limit upward movement of the plunger I2.

Second track means 50 are also secured to the central member I1 by meansof bolts 5I, and comprise an upper portion 52 and a lower portion 53.The lower portion has an upper rounded end 54 and has provided in itssides and upper end a cup-shaped groove 55 adapted to assist inconfining the ball bearings I6. Similarly, the upper portion 52 of thesecond track means 50 is provided with a concave lower end having acup-shaped groove E therein cooperating with the groove 55. The lowerportion 53 of the second track means 5U also has a longitudinal groove51 therein adapted to receive a second tongue 58 formed on the lowermember 35 of the plunger I2, and has a shoulder 59 at its upper enda-cting as an upper stop to limit upward movement of the plunger I2.

A third track means 62 is fixed to the central member I1 similarly tothe second track means 50 and is in all respects identical therewith,cooperating with the plungers I3 and I4 in the same manner that thesecond track means 50 cooperates with the plungers I2 and I3.

A fourth track means 63 is likewise fixed to the central member I1similarly to the first track means 2|, and is similar in constructionthereto. The fourth track means 63 cooperates with the plunger I4 andcloses the end of the retaining means IU.

As will be noted, the ball bearings I6 are retained in the cup-shapedgrooves formed in the track means and plungers, and form a continuouschain of ball bearings therein, each ball bearing of which is separatefrom the others, although they are in linear engagement. It is also tobe noted that the ball bearings I6 are free to flow or move in thecup-shaped grooves provided therefor.

The plunger I2 is provided with an eye member 65 pivoted to the rivet 39and being connected to a suitable cable 66 from which the plunger I2 issuspended. Similarly, the plungers I3 and I4 are connected to suspendingcables B1 and 68 respectively.

In operation, the bearing means I5, through the ball bearings I6,equalizes the tension in the cables 66, B'I, and 6B. If one of thecables, such as the cable 66, stretches so as to normally reduce thetension thereon, the increase in tension caused thereby on the cables 61and 68 as a result of the increase in weight on such cables causes thisincrease in tension to be communicated to the plunger I2 through theball bearings I6 from the plungers I3 and I4, thus equalizing thetension on all of the plungers. Thus,

` it will be understood that any stretching of the cables 56, 61, or 68,due to normal w-ear and use, and the variation in tension which wouldnormally be caused therebetween due to such stretching, will beequalized between the cables immediately by the ball bearingconstruction shown and described. As will be understood, the second setof plungers I2a, I3a, and |4a is designed to be attached to a second setof cables, so as to provide a construction as shown for equalizing thetension between six supporting cables. It will be understood, however,that any desired number of cables and plungers may be used withoutdeparting from the spirit of the invention,

since the invention will operate with two or more cable and plungerconstructions.

Although I have illustrated and described my invention in a preferredform, it will be understood that certain parts, elements, and unitsthereof may be replaced by other parts, elements, and units having thesame mode of operation without departing from the spirit of myinvention, and therefore I do not intend to be limited by the embodimentdescribed but wish to be afforded the full scope of the followingclaims. Iclaim as my invention:

1. In a device of the character described, the combination of: retainingmeans having a continuous channel therein; a plurality of plungersslidably retained in said retaining means each adapted to be connectedto a tension member, each of said plungers having a groove therearoundcooperating with a portion of said channel; and a plurality of ballbearings movably disposed in said channel in contiguous relation andengaging said grooves so as to receive the thrust from all of saidplungers and equalize the tensions in said tension members.

2. In a device of the character described, the combination of: retainingmeans; a rst plunger slidably disposed in said retaining means; a secondplunger slidably disposed in said retaining means; a first tensionmember attached to said first plunger; a second tension member attachedto said second plunger; and a single line of ball bearings in contiguousrelation disposed in said retaining means between said retaining meansand said plungers and adapted to receive the thrust of said plungers,said ball bearings being movable in response to differences in thrustthereon by said plungers to equalize the tensions in said tensionmembers.

3. In a device of the character described, the combination of: retainingmeans; a rst plunger slidably disposed in said retaining means; iirststop means for limiting movement of said first plunger in vsaidretaining means; a second plunger slidably disposed in said retainingmeans; second stop means for limiting movement of said second plunger insaid retaining means; a rst tension member attached to said rst plunger;a second tension member attached to said second plunger; and ya singleline of ball bearings in contiguous relation disposed in said retainingmeans between said retaining means and said plungers and adapted toreceive the thrust of said plungers, said ball bearings being movable inresponse to differences in thrust thereon by said plungers to equalizethe tensions in said tension members. A

4. In a device of the character described, the combination of: retainingmeans; a rst plunger slidably disposed in said retaining means; a secondplunger slidably disposed in said retaining means; a first tensionmember attached to said rst plunger; a second tension member attached tosaid second plunger; walls forming a ball passage in said retainingmeans; walls forming a ball passage in each of said plungers, saidpassages in said plungers and said passage in said retaining meansIforming a continuous passage; and ball bearings in said continuouspassage in contiguous relation and adapted to receive the thrust of saidplungers, said ball bearings being movable in response to differences inthrust thereon by said plungers to equalize the tensions in said tensionmembers.

5. In a device of the character described, the combination of: retainingmeans; a first plunger slidably disposed in said retaining means; asecond plunger slidably disposed in said retaining means; a firsttension member attached to said rst plunger; a second tension member'attached to said second plunger; walls forming a ball passage in saidretaining means; walls forming a ball passage in each of said plungers,said passages in said plungers and said passage in said retaining meanslforming a continuous passage; ball bearings in said continuous passagein contiguous relation and adapted to receive the thrust of saidplungers, said ball bearings being movable in response to differences inthrust thereon by said plungers to equalize the tensions in said tensionmembers; and stop means for limiting the movement of both said plungersrelative to said retaining means.

6. In a device of the character described, the combination of: retainingmeans including a central member and first, second, and third trackmeans secured thereto, said track means having formed therein a ballbearing passage; a first plunger slidably disposed between said rst andsecond track means, said first plunger having a first bearing passagetherein adapted to form a continuous part of said ball bearing passage;a second plunger slidably disposed between said second and third trackmeans, said second plunger having a second bearing passage thereinadapted to form a continuous part of said ball bearing passage, said rstand second bearing passages and said ball bearing passage forming acontinuous passage; a first tension member attached to said irstplunger; a Second tension member attached to said second plunger; and

ball bearings in said continuous passage in contiguous relation andadapted to receive the thrust of said plungers, said ball bearings beingmovable in response to differences in thrust thereon by said plungers toequalize the tensions in said tension members.

7. In a device of the character described, the combination of: retainingmeans including a central member and first, second, and third trackmeans secured thereto, said track means having formed therein a ballbearing passage; a first plunger slidably disposed between said firstand second track means, said first plunger having a first bearingpassage therein adapted to form a continuous part of said ball bearingpassage; a second plunger slidably disposed between said second andthird track means, said second plunger having a second bearing passagetherein adapted to form a continuous part of said ball bearing passage,said rst and second bearing passages and said ball bearing passageforming a continuous passage; a rst tension member attached to said rstplunger; a second tension member attached to said second plunger; ballbearings in said continuous passage in contiguous relation and adaptedto receive the thrust of said plungers, said ball bearings being movablein response to differences in thrust thereon by said plungers toequalize the tensions in said tension members; and stop means forlimiting the movement of both said plungers relative to said retainingmeans.

SAMUEL J. MORAN.

